Businesses compete in markets with significant uncertainty and choose disparate competitive strategies. Some attack while others appear to wait. While real options logic has been used to explain market entry and exit decisions under uncertainty, few have tied this logic to the characteristics of ventures' competitive moves. This paper discusses how ventures launch competitive moves, particularly the speed and intensity of action, under contrasting conditions of exogenous uncertainty and first-mover advantage. We argue that the speed and intensity with which entrepreneurs conduct competitive activities are contingent on both their perceptions of the environment and their level of certain cognitive biases. We conducted a two-by-two within-subjects design experiment to test our hypotheses with a sample consisting of service industry professionals.